The Relation Between the Peak Stress for a Blunt Flaw and the Stress Intensity Factor for an Equivalent Crack

The paper presents arguments to support the view that the often quoted relation σ_p = Lim[μK_I/(πρ)^1/2] as ρ (flaw root radius of curvature) tends to zero, with σ_p being the peak flaw-tip stress, K_I, the effective stress intensity factor, and μ = 2, is strictly valid only for the case of an infinitely deep parabolic flaw. The importance of the parameter μ is highlighted with regards to the problem of fracture initiation at the root of a blunt flaw.